The invention relates to the technical field of multiaxial aiming mechanisms. More particularly, the invention consists in a firing turret mounted on a mobile platform and, more specifically, to means which corrects the tilt angle of a weapon and of the optical sighting device thereof.
The invention as described below relates particularly, but not exclusively, to a firing turret for armored vehicles, but it is to be understood that the means described are equally suitable for a turret susceptible of being inclined and for which it is desired to maintain the horizontality of the pivoting trunnions of the weapon or of the barrel cradle.
The present tendency in the development of weapons is to build weapon systems provided with a continuously increasing mobility; this consideration applies to artillery weapons which have to be mounted on mobile platforms and operate in the first line of battle, such as automotive armored vehicles or towed chassis, so as to permit rapid displacement of these vehicles or platforms between successive points of shooting in order to give, for example, support to infantry units.
An artillery vehicle has to operate on different kinds of ground; consequently, the firing platform is subjected to an inclination which results from the local inclination of the ground. The inclination of the firing platform or, in other words, the non-verticality of the turret, when not compensated, leads to operational limitations in the use of the weapon.
A firing turret with two axes, of the elevational and azimuthal movement type, typically comprises: a means of anchoring on the firing platform; a mechanism for lateral aiming and, supported by this mechanism, an elevationally pivotable cradle on which the weapon is placed.
By construction, the pivoting axis of the cradle is perpendicular to the axis of the barrel of the weapon.
Any inclination of the firing platform results in an inclination of the pivoting axis of the weapon cradle which, in its turn, depends on the lateral aiming direction and on the direction on inclination of the platform. This angle of inclination of the pivoting axis of the weapon cradle is usually called the "tilt angle". The tilt angle causes a variation in the angle of lateral aiming of the arm when the aiming angle of the cradle is modified. In other words, the vertical plane containing the axis of the weapon, i.e. the shooting plane, is rotated when the inclination of the firing platform is modified.
To remedy the above-named fault, mechanisms for aiming or for driving aerial radar have been proposed, mounted on platforms, comprising a third axis, or tilt correction axis, between the axis of azimuthal movement and the axis of elevational movement. In this connection reference could be made to the book of W. M. Cady et al. "Radar Scanners and Radomes", Vol. 26 of the M.I.T. Series, edited by McGraw-Hill in 1948.
There are also known naval artillery mountings including a third axis intended for correcting the tilt of the trunnions of the weapon caused by the inclination of the ship. In the design of such mechanisms this third axis considerably reduces the strength of the mechanism and no means have been provided until now, which would permit the integration of the third axis in an armored firing turret which is also tight against bad weather.
There are further known armored vehicles in which a cradle which bears the barrel, its ammunition magazine and the seats occupied by the weapon operators, is suspended so as to be movable around an axis for correcting the tilt angle. In accordance with the proposed design of this aiming mechanism, its strength is considerably decreased, the wheel clearance of the trunnions is limited, the elevational displacement of the gun requires a second suspension point, and the means for protecting the tilt mechanism from enemy projectiles and from bad weather are extremely complicated.